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Pokemon cards are typically identified by typing in their name, number, and, if applicable, holo. For example: Blastoise 2/102 Holo. If you see a card without a fraction, its probably a promo card
Being the only game in town for no-art lands would make Unstable more similar to Unhinged or Unglued , where if you wanted a certain subgroup of basics for your deck, you pretty much had to buy the set (or at least the lands from the set, which would force someone else to crack a box of the set to sell them to you)
#8 Ninetales is a holofoil card in the base set
Frequently Asked Questions How much is Life Extreme worth
Also, consider how popular a card is